我正在尝试使用图像的坐标在imageIcon上绘制一个填充矩形，并且矩形显示为关闭

Question

Eventually after I work out this small detail it will receive a building and room number to outline said building and room number so it is easy to locate but I can't get the rectangle to draw even close to acurately over a single room.

package programSTLApp;
/*
   Program to request the classroom no. in STLCC and Display the location of 
   that classroom.
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class STLApp extends JFrame
{
    private JLabel imageLabel;
    private JButton button;
    private JPanel imagePanel;
    private JPanel buttonPanel;

public STLApp()
{
    super("My STLCC Class Locator");   

    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new BorderLayout());
    buildImagePanel();
    buildButtonPanel();

    add(imagePanel, BorderLayout.CENTER);
    add(buttonPanel,BorderLayout.SOUTH);

    pack();
    setVisible(true);
}

private void buildImagePanel()
{
    imagePanel = new JPanel();
    imageLabel = new JLabel("Click the button to see the drawing indicating "
            + "the location of your class");
    imagePanel.add(imageLabel);
}

private void buildButtonPanel()
{
    buttonPanel = new JPanel();

    button = new JButton("Get Image");

    button.addActionListener(new ButtonListener());
    buttonPanel.add(button);
}

private class ButtonListener implements ActionListener
{
    @Override
    public void actionPerformed(ActionEvent e)
    {
        ImageIcon SiteLayoutFV = new ImageIcon("D:\\B120.jpg");
        imageLabel.setIcon(SiteLayoutFV);
        imageLabel.setText(null);
        pack();
    }

}
public void paint(Graphics g)
    {
        super.paint(g);
        g.setColor(Color.RED);
        g.fillRect(55,740,164,815);
    }


    public static void main(String[] args) 
    {
        new STLApp();


    }
}

Answer 1

As has already being pointed out, top level containers ain't a studiable class for performing custom painting, there is just to much going with these containers to make it easy to paint to.

Instead, create yourself a custom component, extending from something like JPanel , and override it's paintComponent method.

Once you have the floor pane rendered, you can render you custom elements over the top of it.

How you store this information is up to you, but basically, you need some kind of mapping that would allow you to take the floor/room and get the Shape that should be rendered.

Because the floor map might float (it may not always be rendered at 0x0 for example), you need to be able to translate the coordinates so that the Shape will always match.

Take a look at...

• Performing Custom Painting
• 2D Graphics

For more details

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class FloorPlan {

    public static void main(String[] args) {
        new FloorPlan();
    }

    public FloorPlan() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private BufferedImage floorPlan;

        private Rectangle myOffice = new Rectangle(150, 50, 32, 27);

        public TestPane() {
            try {
                floorPlan = ImageIO.read(new File("floorPlan.png"));
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return floorPlan == null ? new Dimension(200, 200) : new Dimension(floorPlan.getWidth(), floorPlan.getHeight());
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            if (floorPlan != null) {

                int x = (getWidth() - floorPlan.getWidth()) / 2;
                int y = (getHeight() - floorPlan.getHeight()) / 2;
                g2d.drawImage(floorPlan, x, y, this);

                g2d.setColor(Color.RED);
                g2d.translate(x, y);
                g2d.draw(myOffice);

            }

            g2d.dispose();
        }
    }

}